Inclosed fuse.



PATENTED NOV. 2l, 1905.

C. D. HASKINS.

INGLOSED FUSE.

APPLICATION FILED JUNE 24.1904.

Inventor Caryl D. llaskn WitrweSses:

. metallic terminal blades 4,

NITED STATES PATENT OFFICE.

CARYL D. HSKINS, OF SCHENECTADY,

NEW YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEWYORK.

' INCLOSED FUSE.

Specification of Letters Patent.

Patented Nov. 21, :1905.

Application filed June 24:, 1904. Serial No. 213,940.

To all whom it may concern.-

Be it known that I, CARYL D. HAsKINs, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in InclosedFuses, of which the following is a specification.

The present invention relates to thermal cut-out devices for use ininterrupting electric circuits upon the passage of abnormal currents,and has for its object the provision of a device of this character whichwill act more positively and safely than the cut-out devices heretoforein use.

In the practical embodiment of my invention I provide a suitable casingor shell having electrical terminals for engagement with the usualcontacts, and within this casing are arranged a cavity with acollapsible wall, a shutter adapted to move toward the cavity under thestress of a spring or similar device, but normally sustained inretracted position by the fusible conductor passing through the casingand electrically connecting the metallie terminals at the ends, and anabsorbent powder loosely filling the space between the end of theshutter and the collapsible wall and surrounding more or less of themiddle section of the fusible conductor, so that when the fusibleconductor is disrupted or greatly weakened by excess current the shutterinstantly moves forward under the stress of its spring, forcing thecollapsible wall into the cavity and compacting by a shearing movementthe absorbent powder about the severed ends of the fusible conductor,and thereby interposing a barrier and effectually smothering any arcthat tends to form at the time of rupture of the fusible conductor.

For a more complete understanding of my invention reference may be hadto the following detailed description and the accompanying drawing,forming a part of this specilication, in which is shown in longitudinalsection a standard cartridge-fuse with my invention applied thereto.

The shell or casing consists of a tube l of fibrous insulating materialprovided at its ends with metallic thimbles or caps 2, secured inposition by screws 3, extending through the flanges of the thimbles andentering screwthreaded holes in the sides of the tube, and riveted tothe ends of the caps 2.

The fusible conductor consists of a strip 5 of metal or alloy connectedto the lower terminal, extended upwardly adjacent the inner surface ofthe tube 1 at one side to about the middle of the tube length, where itis bent at right angles and led to the opposite side of the tube andthen bent up parallel to its first course and led along' the innersurface of the tu ble to the terminal at the Lipper end of the she l.

The cavity 6 is formed in the upper end of a cylindrical block ofsuitable insulating material, such as unglazed porcelain or chalk, whichsubstantially fills the tube 1 for about one-half its length and has atits upper end a shoulder 8, upon which the transverse section of thefusible conductor 5 rests. The side walls of the cavity 6 are in theform of an inverted cone, and at their Lipper' end a ledge 9 is formedupon which the collapsible wall 10, consisting of a disk of paper orother readilyfoldable material, is placed. From the ledge 9 the materialof the block 7 is cut away to provide an upwardly-flaring opening to thecavity 6.

The movable shutter 11 is of the same material as the block 7 and has aconical projection l2 at its lower end and a cylindrical chamber 13 atits upper end for the reception of a light spring 14, which is arrangedto bear against the inner side of the upper cap 2 and the bottom of thechamber 13. The conical projection 12 has near its point a smalltransverse aperture 15, through which the fusible conductor 5 isthreaded at its transverse section. An air-space is provided about thecentral section of the fuse by means of a channel 16, formed in theshutter 1l and extended axially from the bottom of the chamber 13 andintersecting the aperture 15.

The absorbent powder 17, which fills the space about the fusibleconductor 5 between the adjacent ends of the block 7 and the shutter ll,may be of any of the various kinds employed for absorbing and condensingmetallic gases.

When an excessive current passes through the fusible conductor 5, thelatter .tends to heat up throughout its entire length; but by reason ofthe heat conductivity of the materials in immediate contact therewiththe point of actual rupture will be confined to the portion extendingthrough the air-space 16. As soon as the fusible conductor 5 becomesrup- IOO tured or greatly weakened the shutter 11 moves under the recoilof the spring 14E toward the cavity 6, breaking in the collapsible wall1() and plunges its point 12 and a portion of the powder 17 into thevacant space and at the same time interposing the insulating-barrier ofits body part between the severed ends of the fusible conductor andforcing the absorbent powder 17 into intimate Contact with the conductorends, thereby effectually smothering any arc that may have formedbetween them at the instant of rupture.

rounding said-conductor, and a shutter provided with an air-spacethrough which the said conductor is threaded.

6. The combination with a fusible conductor, of a support thereforprovided with a vacant space, an absorbent insulating material, and ashutter adapted to move between the severed ends of said conductor intosaid vacant space and to force said absorbent material into intimatecontact with said ends upon disruption of said conductor.

7. rI he combination with a fusible conductor and casing therefor, of avacant space or It is apparent that the form and construcl chamberarranged in said casing and provided tion of parts herein described andshown may be changed and modified without departing from my invention.

What I claim as new, and desire to secure by Letters Patent of theUnitedv States, is-

1. The combination with a fusible conductor, of an absorbent insulatingmaterial, and means to force said insulating material into intimatecontact with the ends of said cond uctor upon disruption thereof.

2. The combination with a fusible conductor, of an absorbent insulatingmaterial, and means to separate the severed ends of said conductor andto force said insulating mate- -rial into intimate contact therewithupon disruption of said conductor.

3. The combination with a fusible conductor, of an absorbentinsulatingmaterial, and means to interpose abarrier between the severedends of said conductor and to force said absorbent insulating materialinto intimate contact with said ends upon disruption of said conductor.

f1. The combination with a fusible conductor, of an absorbent insulatingmaterial, and a biased shutter normally held in retracted position bysaid conductor and adapted upon disruption of the latter to move betweensevered ends of the conductor and force the said absorbent insulatingmaterial into intimate contact with said ends.

5. The combination with a fusible conductor, of an absorbent insulatingmaterial surwith a collapsible wall, a shutter normally held inretracted position, and an absorbent insulating` material filling thespace within said casing between the end of said shutter and saidcollapsible wall. l

8. The combination with a fusible conductor and its casing, of aninsulating-block in said casing provided with a vacant space or chamberhaving a collapsible wall, a springpressed shutter normally held inretracted position by said conductor, and an absorbent insulatingmaterial loosely filling the space within said casing between the end ofthe shutter and the said collapsible wall.

9. The combination of a casing, a fusible conductor extendingtherethrough and provided with a central transverse portion, aninsulating-block having at one end a shoulder for engaging thetransverse portion of said conductor and a vacant space or chamberprovided with a collapsible wall, a spring-pressed shutter normally heldin retracted position away from said collapsible wall by the fusibleconductor, and an absorbent insulating material filling the spacebetween the adjacent ends of said block and shutter.

In witness whereof I hereunto set my hand the i this 23d day of June,19011.

CARYL D. HASKINS.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

